Differential commutator



NOV- 15, D B SEVIN DIFFERENTIAL COMMUTATOR File Ja 951 2 Sheets-Sheet 1 ELEC TR/CRL C lRCU/T PLURHL CIRCUITS INVENTOR. Fl 4 Dal/6M5 B. Sew/v BY Q6. M

H770 NEYJ Nov. 15, 1955 D. B. SEVIN 2,724,025

DIFFERENTIAL COMMUTATOR Filed Jan. 2, 1951 2 Sheets-Sheet 2 Douams 5. 5.; w/v

United States Patent DIFFERENTIAL COMMUTATOR Douglas B. Sevin, Quaker Hill, Conn.

. Application January 2, 1951, Serial No. 204,056

Claims. (Cl. 200-25) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to the art including time-interval controllers, and more particularly, it relates to mechanical arrangements for controlling the on and oli periods of electric signals.

A principal object of the invention is to provide an interval controller that is operable at high speeds to define exceedingly small periods.

Another object is to provide such a controller that is readily adjustable over relatively wide ranges of time interval values. I

Still another object is to provide such a controller. that is adapted for smooth operation, evidencing substantially no discontinuities during relatively high-speed opening and closing of electric circuits.

Yet another object is to provide a mechanical interval timer that is simple in construction, dependable of operation and easily adjustable over a wide range of operating conditions.

' A'feature of this invention resides in the provision of an apparatus for controlling intervals of circuit continuity, which comprises a pair of spaced conductive elements movably mounted with respect to contactor means adapted to effect closed circuit condition therebetween, said elements. being relatively adjustable for varying the respective periods of the said conditions.

Another object of this invention resides in the provision of mechanical commutator arrangements adapted for synchronizing the actuation of a plurality of circuits, said arrangements including means individually altering the adjustment of timing of one said circuit independently of the timing of the other circuits.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is an isometric view, with parts broken away, of a time-interval controller embodying the invention,

Fig. 2 is an exploded view of the controller of Fig. 1,

Fig. 3 is a cross-sectional view taken along the line 3--3 of Fig. 1, and I Fig. 4 is a perspective view of a modification of the invention.

. Figs. 1 and 2 show an interval timer or controller constructedin accordance with the principles of this invention. A cylindrical housing 11 is formed of insulating material and with relatively smalland large-diameter bore portions 13 and 15, respectively. The junction of the bore portions 13, 15 defines an inwardly extending shoulder 17 (Fig. 2) of which an arcuate part 19 is recessed to receive a conforming arcuate conductive segment 21, which is adapted to be secured in the recessed part in any suitable manner as, for example, by screws 23.

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A cooperating conductive segment 25, of arcuate formsimilar to that of segment 21, is embedded in a corresponding recess formed in the end of an insulating ring 27 and therein suitably secured as by screws 29.

The segments 21 and 25 are insulatingly spaced from each other by a non-conducting ring 31, which snugly fits in the large-diameter bore portion in abutting relation to theshoulder 17 and the outer face of the segment 21.

The inner diameter of ring 31 is somewhat larger than the inner diameter of the small-diameter bore portion 13 so that when the segments 21, and rings 27, 31 are assembled, as shown in Fig. 1, and secured in assembly as by overlapping engagement of the caps of screws 32 and the outer end of ring 27, a shallow circumferential trough 33 is formed of which the walls are the exposed adjacent faces of segments 21, 25, shoulder 17 and inner edge of ring 27, the floor of the trough 33 being the inner periphery of ring 31.

A rotary contactor assembly 35 is supported axially of the housing 11 and is adapted to be driven by any suitable motive means (not shown) through a shaft 37. The contactor assembly 35 consists of a hub 39 adjustably secured to shaft 37 as by set screw 40, and having radially extending anchor and pivot members 41 and 43, respectively, which resiliently support a bellcrank 45 having a bevelled conductive wheel 47 journalled at the free end thereof. For dynamic balancing of the rotor, the bellcrank 45 is designed so that the wheel 47, in normal operating position, is substantially diametrally opposite the anchor member 41, with a spring 49 exerting sufiicient tension to cause the bevelled edges of wheel 47 gently to bear against the inner edges of the upper parts of the trough walls, as shown in Fig. 3. I

Thus, as the wheel 47 revolves in the trough 33, it also rotates about its own axis 51, and during a revolution of the rotor assembly, substantially point conductive connection between segments 21 and 25 is effected during the time that the wheel 47 simultaneously contacts the segments. Electrical contact is broken when only one segment or no segments are contacted by the wheel 47.

The length of simultaneous contact time can be varied, according to this embodiment of the invention, and even while the rotor is spinning on its shaft, by making one of the segments, here segment 25, angularly adjustable relative the other segment 21. Thus, as shown, ring 27 is provided with a capped guide pin 53 threaded into a suitable opening in the wall of the ring. Pin 53 extends radially through a semi-circumferential slot 55 formed in the wall of housing 11, and when screwed down, the cap of pin 53 bears against the outer edges of the walls of sl0t 55 and frictionally holds ring 27 in position. Loosening pin 53 frees ring 27 for angular displacement resulting in a corresponding angular displacement of segment 25 relative segment, 21.

Segment 21 can be connected to an external circuit 56 by means of a terminal 57, which extends through a radial slot 59 formed in the large-diameter bore portion 15 of housing 11. Connection of segment 25 to the external circuit is effected by a screw 61 and tab 63 arrangement, with the screw 61 establishing conductive connection to segment 25.

. A modification of the timer apparatus of this invention is shown in Fig. 4. According to this .version, a pair of insulating discs 65, 67 are individually adjustably mounted on a common sleeve 101, which is itself adjustably carried on a shaft 69. Simultaneous or conjoint adjustment of discs 65, 67 in shaft 69 is accomplished by means of set screw 103. Rotation of shaft 69 can be produced by any suitable motive means 71. As shown, discs 65, 67 are provided with integral or suitably at tached collars 73, 75, each having set screws 77, 79 by U meansof which the respective discs can be secured to the sleeve 101. It will be apparent that the means for securing the discs to the sleeve 101, and sleeve 101 to shaft 69 are exemplary only and that any other suitable means can be employed providing for both individual and conjoint adjustability of the discs 65 and 67.

The conjoint adjustability of the discs is particularly. advantageous where it is desired to use the controller to control or synchronize a plurality of circuits 105. In such a case, multiple pairs of discsconstructed similarly to discs 65, 67 each having suitably designed segments may be used; Each such pair is individually adjustably mountedon respective sleeves, which sleeves, in turnare adjustably mounted on the shaft. Discs 93, 95, to be more fully described herebelow, are illustrative of such another pair of' discs. In this" manner, provision is made for independent adjustment of the. timing of'individual circuits indefinitely or in synchronism with that of other circuits'.

As shown in Fig. 4, conductive. arcuate segments 81, 83 are'embedded' in a' peripheral portion of discs 65, 67, respectively, and the segments are conductively interconnected by'a conductor 85 that is soldered or'otherwise attached at its ends to the segments 81, 83.

Connection to-the external'circuit 105 to be controlled is'effected by means of roller brush contactors comprisingconductive rollers 87, 89 rotatably supported at the end'of' spring members 91, 93, respectively, so that the rollers gently bear against and contact the peripheries of discs 65, 67. The spring" members 91, 93' are afiixed at their opposite ends to a terminal strip 95.

In operation, the rollers 87, 89' ride along the peripheriesof'the associateddiscs 65; 67 as the latter'are caused to' rotate. When both rollers are in simultaneous contact with the conductive segments'81, 83 ofthe respective discs, the circuit is closed; at all other times the circuit is open.

The duration of the closed-circuit condition is readily altered by adjusting the relative orientation of the discs 65; 67". Thus, when the conductive segments 81, 83 are in completejuxtaposition, the conductive time intervalis a maximum. As the relative positions of the conductive segments are altered such that only parts of the segments are in a juxtaposed relation, the conductive time intervals are correspondingly reduced.

Where it is desired to open a normally closed circuit for adjustable short intervals, conductive discs 93, 95 can be employed each having'respective insulating segments 97, 99 arranged in a manner similar to that of" the conductive segments 81, 83 on the insulating discs 65, 67. Here also, the duration of'the desired time interval is varied by adjusting the relative orientation of" the discs.

In the" foregoing description of the embodiment of the invention illustrated in Figs. 1-3, a single pair of cooperating segmental rings and associated contactor assembly are'disclosed. It'will be apparent, however, that where a plurality of circuits are to be controlled in synchronism or other timed sequence, a corresponding plurality of pairs of segmental rings can be provided, each pair'having a respective rotor similar to rotor 35- (Fig. 2'), all-individually adjustably mounted on the same shaft. Such additional pairs of rings and the associated rotors would thus beindividually adjustable to afford any desired time relationship among the respective'circuits;

Thus, when a plurality of time-interval controllers are usedand after having been preliminary synchronized as by relaxing the set screws in the respective hubs and rotating the plural rotor assemblies" relativetheir common shaft until a desired alignment or synchronization is achieved, the time interval of each may be varied without disturbing the synchronization. For example, if the adjustable conductive segment is positioned with respect to the fixed segment in each controller in such manner that the adjustable segment is first contacted by the associated conductive wheel, the time intervals of all controllers begin simultaneously. Similarly, if the adjustable segment is positioned relative to the fixed segment in each controller in such manner that the fixed segment is first contacted by the associated conductive wheel, the time intervals of all controllers end simultaneously.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced' otherwise than as specifically described.

I claim:

1. Adjustable switch mechanism for electric circuits, comprising a pair of rotatable disc members, each, said member having peripheral conducting. and insulating. parts, the conducting parts of" said members being. con} ductively interconnected, means for adjusting the connected members relatively to'each otherto vary the spatial alignment of the respective conducting and insulating parts, and a conductive rotatable wheel contacting. both of said members for connecting said conducting partsto the electric circuits, whereby upon adjustment of said connected members selective electric conduction of said circuits is. obtained for predetermined time intervals.

2. The mechanism defined in" claim 1 wherein said wheel comprises roller brush means yieldably, mounted for pointrolling contactalong the periphery of said disc members.

3. The mechanism defined in claim 1' wherein said contact means comprises roller brush means including. a V-shaped roller edge, said roller brush means being mounted. yieldably for rolling; contact along the periphery oflsaid disc members,

4. Rotary switch apparatus for anelectri'c circuit, com.-. prising relatively rotatable elements, one said element. having. spaced conductive parts and spaced insulating. parts, means to re-orient said, parts; the other said element; comprising a conductive contactwheell adapted? for periodic. simultaneous conductive. engagement with said. conductive parts, and means for coupling said elements. to. the.cir.cuit.

5.. Electric currenteeontrolling apparatus. comprising rotary means interrupting the current circuit periodi cally, said rotary means. comprising a stator andia rotor, said stator having apair. offrelatively adjustable segmented. rings disposed in. spaced coaxial. alignment, said rotor in: cludinga conductive roller. supported'rotatahly for simul taneous engagement withsaidrings, and means. for vary-. ing the.period..0f the. interruptions.

Bitler .Aug.. 29., 1950 

